The conventional crash helmet worn when riding a bicycle has a ring-band installed inside to fix on the head of the user. The diameter of the ring-band is fixed and can not be adjusted properly according to the head of the user, resulting in unsteady positioning and uncomfortable wear.
The primary object of the present invention is to provide a ring-band adjustment structure of the crash helmet, which comprises a ring-band, a connection part and two adjustment part. The accommodation groove of the connection part has two positioning teeth with their teeth end on the top side. The two adjustment parts are connected to the two ends of the ring-band. The two adjustment parts are slid to match the position teeth. The two adjustment parts can be in the lock state or the adjustment state. The diameter of the ring-band can be adjusted properly according to the head of the user, resulting in steady positioning and comfortable wear. Moreover, the positioning teeth are formed on the connection part. Simple structure and easy assembly thus make the production cost be reduced greatly.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: